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STANDARDSIST-TS CEN/TS 15558:20081DGRPHãþD
SIST EN 15558:2009
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15558January 2009ICS 65.080Supersedes CEN/TS 15558:2007
English VersionFertilizers - Determination of nitric and ammoniacal nitrogenaccording to UlschEngrais - Dosage de l'azote nitrique et ammoniacal selonUlschDüngemittel - Bestimmung von Nitrat- undAmmoniumstickstoff nach UlschThis European Standard was approved by CEN on 30 November 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15558:2009: ESIST EN 15558:2009
EN 15558:2009 (E) 2 Contents Foreword .31Scope .42Normative references .43Terms and definitions .44Principle .45Reagents .46Apparatus .57Sampling and sample preparation . 108Procedure . 109Calculation and expression of the result . 1110Test report . 12Bibliography . 13
SIST EN 15558:2009
EN 15558:2009 (E) 3 Foreword This document (EN 15558:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2009, and conflicting national standards shall be withdrawn at the latest by July 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS 15558:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 15558:2009
EN 15558:2009 (E) 4
1 Scope This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch. The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1482-2, Fertilizers and liming materials — Sampling and sample preparation — Part 2: Sample preparation EN 12944-1:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 1: General terms EN 12944-2:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 2: Terms relating to fertilizers EN ISO 3696:1995, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999 apply. 4 Principle Reduction of nitrates and nitrites to ammonia by means of metallic iron in an acid medium and displacement of the ammonia thus formed by the addition of an excess of sodium hydroxide: distillation of the ammonia and determination of the yield of ammonia in a known volume of standard sulfuric acid solution and titration of the excess sulfuric acid by means of a standard solution of sodium or potassium hydroxide. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and distilled or demineralized water, free from carbon dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995). 5.2 Diluted hydrochloric acid Mix one volume of concentrated hydrochloric acid solution, ρ(HCl) = 1,18 g/ml, with one volume of water. SIST EN 15558:2009
EN 15558:2009 (E) 5 5.3 Sulfuric acid, c = 0,05 mol/l. 5.4 Sodium or potassium hydroxide solution, carbonate free, c = 0,1 mol/l. 5.5 Sulfuric acid solution, approximately 30 % H2SO4 (mass concentration), ammonia free. 5.6 Powdered iron, reduced in hydrogen. The prescribed quantity of iron shall be able to reduce at least 0,05 g of nitrate nitrogen. 5.7 Sodium hydroxide solution, 30 % mass concentration, of approximately ρ(NaOH) = 1,33 g/ml, ammonia free. 5.8 Indicator solutions 5.8.1 Mixed indicator Solution A: Dissolve 1 g of methyl red in 37 ml of sodium hydroxide solution c = 0,1 mol/l and make up to 1 l with water. Solution B: Dissolve 1 g of methylene blue in water and make up to 1 l. Mix one volume of solution A with two volumes of solution B. This indicator is violet in acid solution, grey in neutral solution and green in alkaline solution. Use 0,5 ml (10 drops) of this indicator solution. 5.8.2 Methyl red indicator solution Dissolve 0,1 g of methyl red in 50 ml of 95 % ethanol. Make up to 100 ml with water and filter if necessary. This indicator may be used (4 to 5 drops) instead of that specified in 5.8.1. 5.9 Anti-bump granules, for example pumice stone, washed in hydrochloric acid and calcined. 5.10 Sodium nitrate, p. a. 6 Apparatus 6.1 Distillation apparatus Consisting of a round-bottomed flask of suitable capacity connected to a condenser by means of a splash head. The equipment is made of borosilicate glass. NOTE The different types of equipment recommended for this determination are reproduced, showing all the features of construction, in Figures 1, 2, 3 and 4. An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. SIST EN 15558:2009
EN 15558:2009 (E) 6 Dimensions in millimetres
Key 1 round-bottomed, long-necked flask o
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